This application relates to a method of verifying that the sensors disposed in a plurality of zones in a multi-zone heating, ventilating and air conditioning (HVAC) system are properly associated with corresponding zone dampers.
In a typical ducted HVAC system, a blower in an indoor air handler circulates air to various parts of the home through a system of ducts. In a typical zoned HVAC system, the ducts are divided into several zones, one for each part of the building that is desired to be controlled independently of the other areas. A set of dampers is installed into the ducts, with at least one damper for each zone. These dampers can be opened or closed, to direct more or less air to a particular zone as needed to satisfy the desired comfort level in that zone. Generally, a system control controls the operation of the ducts. A desired comfort level is set as desired room temperature set point for each zone in the home, and as set by the user.
In one prior art system, a user, such as a homeowner, can set this desired room temperature level for each zone at a main user interface or system control, which is also the thermostat of a first zone. Alternatively, set point controls can be placed in each zone.
Each zone has a temperature sensor that measures the actual room temperature in the zone and electrically transmits its value to the system control. The system control then compares the actual temperature in each zone to its respective desired set point. If one or more zones are not at the desired temperature level, the system turns on cooling or heating equipment (as needed) and opens the dampers of those zones. In this manner, cooling or heating capacity is delivered to every zone, as needed, to enable the sensed actual temperature of the zone to match the desired temperature for each zone. In more advanced systems, not only can the dampers be fully opened or closed, but they can also be modulated to a number of positions in between, to achieve a more precise level of comfort control.
As mentioned, zoned HVAC systems have temperature sensors for each zone and, correspondingly, dampers in the duct system that direct temperature conditioned air to each zone. During typical installation, all sensors and all dampers are wired to the system control. Since dampers are in the duct system and sensors are typically on the wall in each zone, it is important that the damper(s) for each zone, as wired, properly correspond to the sensor for the same zone. Otherwise, the zoning system cannot operate properly and maintain desired comfort in all zones. The system control could command a damper to open to correct a particular zone's temperature difference, and would be controlling the damper of the wrong zone.
However, if such a wiring error is made, the comfort problem may not be immediately apparent. Depending on the homeowner's set points and outdoor conditions, some zones may not need any conditioning for long periods of time, and the effects of wiring errors may not be noticed until then. An installer has no easy way to verify proper installation without waiting for the right set of conditions to develop.
The above prior art system does provide a method for verifying proper installation. From the system control, the installer can command the dampers associated with any zone to open. The installer then must go to that zone and verify that air is being delivered from its registers. This method does verify if the damper is operating, but it does not verify if it is responding to the correct sensor. Also this method requires the installer to go back and forth between each zone and the system control.